Train-dispatching system for railroads



Dec. 16, 1930. s. N. WIGHT TRAIN DISPATCHING SYSTEM FOR RAILROADS 2 Shets-Sheet 1 Filed July 14, 1928 mm on fiedgws sa wwf m.

Dec. l6, 1930.

S. N. WIGHT TRAIN DIS'PATCHING SYSTEM FOR RAILROADS Filed July 14, 1928 2 Sheets-Sheet 2 FIG.2.

INVENIOR N. Wfgh fl /674 14357 hlSATTORNEY Patented Dec. 16,1930

se smic-s PATENT oFFIcE sensi ize n. winne on nocnns'rnn, new YORK, Assmnon T0 GENERAL RAILWAY 1 SIGNAL COMPANY, or noonss'rnn, new YORK TRAIN-DISPATCHING SYSTEM FOR RAILROADS Application filed July 14,

, such single traoksectien is determined by the sequence in which the levers are operated and thejsequence in which the 'two control relays are ene 'gi-Zed. l nrnysaid prior application itcertai-n direction of travel has been set u-p in a,single tracksection by a particular sequence of lever movement, this direction up of travel can be disturbed and the re verse direction of travel accidently setup, as-

tor instance by a train entering such single tracl'csection .at an intermediatepoint, possibly co ning ofl' ore spur track, or by worknennioinentarily drop-pingva track relay, as

ra tionoi'r' traflic set up coining about by reason bygetting a steel crow bar a'cross the track This accidental reversal in the direcof momentary:wblocking of train travel in both; directions, and. it conditions are, restored one of the twotumble-down circuits rning opposite direction of train travel 'toredand the :fi rst one tobe restored in b'revailand setup itsdirection of travel and hrevent the other tumble-down circuit fein restored. in other words, in my prior ication the direction of travel set up by i 'nce o'f lever movement was determined by the control relay which first caused a turnledo-wn circuit to drop all of the horne re lays associated therewith, 1

In accordance with the present invention, taking}; into consideration the foregoing, it is proposed to determine the direction of train travel by the sequence or lever movement and to provide means for preventing trafiic to be set up in an opposite direction to that deterininedbysuchsequence. The net result tobe 'acceinniished, in accordance with the present invention isthat if the direction of traiiic set up is disturbed for any of the reasons 1928. Serial m. 292,833.

above mentioned, such direct-ismoi travel setup will be .restored after such disturbance has terminated.

More specifically, it is proposed to employ a specialor directional stick relay at each end of each single track section, and to permit one oi these stick relays to pick up only in the event-the other stick relay is still de energized, as determined through the associated tu1nbledown circuit.

In this connection it should be remembered that a short tune is required for a tumble down circuit to respond to the picking up of'the stick relay. Another feature of the invention resides in the provision of indicating means for inclicating when traiiic is blocked in both directions as a result of operating the two levers 'associated'with a particular single track section too quickly in succession.

Qther objects, purposes, and characteristic features of the invention will in part be described hereinafter and in part be obvious the accompanying drawings.

In describing the invention in detail reference ,wilil bemade to the vaccoinpanying drawings in which y F 1g. shows conventionally an embodi- .ment of the present n ventmn applied only 7 to one particular single track section of asingie track railway itroui which the indicating;

means has been omitted; and

Fig. 2 shoyvs the same system, together with indicating means at the tower for indicating track circuit occupancy and indicating when trafiic is blocked in :both directions as a result of both of two supplementalstick relaysbein g in their energized condition;

Referring to Fig. 1 of the drawings, showinga single track sectionO of a trailway system having absolutepermissive-block signa=l-;

ing,as more completely shown in my prior application above mentioned, and including the passing sidings PS and PS The starting signals for the passing siding PS has been designated 2 and 2 and the entering signals for this passing siding PS have been designated 1 and 1 The exponent d indicated dwarf or take-siding, as the case may be. The starting signals at the west end of passing siding PS have been designated;

siding PS includes. a switch S2. 7

associated with these'switches S and S are protected by detector track circuits including 7 the detector relays DT and DT respective- 7 and 7 and theentering signals have been designated 8 and 8 The intermediate signal for west bound traffic has been designated 3,

and the intermediate signal for eastbouinfl tratlic has been designated 6. Although the signals may be of any-suitable construction such as colorlight or position light signals,

tor convenience semaphore signals only have been illustrated without showing their wellknown control mechanisms and ClI'GllltS;

These signals are controlled by home relays such as 1H, 2H, 3H,,6H, 7H, and 8H, each having a number corresponding with the,

number of the signal. These various home relays are three-position orpolar neutral re lays, and are capable of controlling the corresponding signals to anyone of three indicat- .ing 1 conditions in a Well-known manner, through circuits for conveniencenot lllustrated. Each of the intermediate signals, of

which there maybe a large number, such as v signals 3 and Sis provided withthe usual directional stick relay, such as relays 3S and 6%, respectively, The passing siding PS includes a track switch S and the passing The signals lyfcontrolled'by the track batteries illustrated. The remaining-track circui'ts'ot single} track section 0, divided'by insulating joints 4, include track relay 1T, 3T, GT, and

81 each of which is connected to a track circuit including a track battery as illustrated.

The starting signals 2, 2 7 and 7? are providedwvith signal blade-operated contacts 10, 11, 12, and 13, respectively; these contacts assuming the position shown whenthe signal blades, by which they are operated, assume the danger or stop position. f

Let us now consider'the tumble-down cir- -cuit forblocking west bound trafic, namely, I the tumble-down circuit controlling the home frelays' 3H and 7H. In'this connection it should-be noted that. the home relay 3H is energized by the following circuit :-starting at; the battery B, back contact 15 of the auX- illiar-y stick relay Z3 contacts 10 and 11 controlled by the signals 2 and 2 respectively, a front contact'16 ofthe detector'track relay .DTflcontact 17 of the track relay 1'1, and

mo ma 18 otthe track relay EST." Also it should" benoted that de-energization of the ionic relay 3H will cause de-energization of the home relay7H unless the stick relay SS is up. I The energizing circuit, for the home -rela'y7H comprises of the following: beginning atB of a suitable source of current,

front conta'ct'20 of the home relay 31-1 or contact 19 01:" the 'stick relay 38 back contact 21 of the stick relay 68, front contact 22 of thetrack relay 6T,tront contact 23 of the track relay 8T, front contact 24:. offthe detector track relay DT through the winding of relay 'T'Hto the'common return Wire C connected to the other side of said source. I

in the same way the home relay "61-1 is energized by the following; circuit -beginning atthe terminal B, back contact 25 of the auxiliary stick relay Z8 signal blade operated contacts 13 and 12 01" the signals"? and 7 respectively, contact 26 or" thedetect-or relay DT", contact27 ofthe track relay 81, contact 28 ofthetrack relay 6?] through the winding of relay 6H to common return C. The circuit for thehoine relay 2H is controlled by home relay 6H and may be traced astollowsz-beginning at the terminal B,

front contact 30 of the relay 6H or front con 5;;

tact 29 of the stick relay 6S, back contact 31 of the'stick relay 38, front contact" 32 of the track relay 3T, front contact ggjofthe track relay 1T, trout contacted of the detector track relay DT throughthejwinding of relay 2H to the common returnvvire C. v V

' It is thus noted thatenergiz'ation of the auxiliary relay ZS? at the west end "of the sin le traclcse'ction U is manifested by drop ping of the'home relay 7H attheeast'end or":

this single track section; and conversely, energ zation ot the auxiliary stick relay Z8 at the east ,end of the single-track sectlonO relays determinesfthe energi'zation' of the home relay adjacent to the otherauxiliary relay,'so that these stick relays are in fact interlocked through the tumbleQdown circuits. A I Y t The system under consideration is,con

trollet from a dispatchers oiiice convention ally illustrated'by the dotted rectangle-DO.

The signals atv thewest end of singletrack.

section 9 are governed by a control relay Z r and the signals at the east end of said single track section are controlled by control relay 2?, these signal control circuits have been shown in part but need not be described in view or" the disclosure inmy prior application. These.control relays. Z andZ are polar-neutral relays in the particular ar i rangement shown, although three position relays'may be used, and they are controlled 7 r by levers L and L respectively, located in thedispatcherls ofice DO;

Operation Fig. 1.Let us assume that the. f

dispatcher in the dispatchers otlice DO wishes to permit tratlic tomove in aneasterly direction, from left to right, andin order to do so moves the lever L 'tothe right hand dotted position. Wrth the lever L assuming the right hand dotted position the control relay-Z located at the distant passing sid- -l11g P'S '1S energized through the following circuit :-Beginning at the battery 40, wires 4 1 and 42, contact of the lever L ,wire 43,

riding the home relay 2H is in its energized concht-ion, and through the following circuit :starting at the terminal 13 of a suitabl e current source, front contact 45 of the home relay 2H, wire 4'5, lront contact-47 of thecontrol relay Z wire l8,windingof the auxiliary stick relay Z8 to the common return wire C. connected to the other terminal of said source;

3 The completion of this circuit causes the r auxiliary stick relay ZS to assume its energzed condition. As soonas it has assumed suchienergized condition it will be stuck up 1 th'iroughjthe following stick circuit :beginning at the terminal'B, front stick contact 50 of the relayZS wires 51 and d6, front contact 47' of the control relay Z wire 48, wind king or stick relay ZS? to-the' return wire C.

-With this'stick relay ZS in its energized condition the tumble down circuit blocking west bound trafiic is broken at the contact 15, and the home relay 3H and 7 H are 'deenergized.

The dispatcher will nextoperate his lever L to the right hand position (assuming that east boundtra'llic is to enter the main'track "of passing siding PS ),and with the lever L 'in the right hand position for the follow ing circuit for. the control relay Z is closed starting at the battery 40, wires 41 and 55, contact of the lever L in the right hand dotted position, line wire 56, winding of the control "relayZ common return wire BC to the middle'point of battery'40. The completion of this circuit causes the control relay Z to assume its rightlhandenergized position and causes it to close its neutral. contacts, thereby tending to cause the signal to assume the clearposition; This signal -7 cannot; however, be cleared because the home relay is in its de-energized condition. Also, with the control relay Z energized the pick up circuit for the auxiliary stick relay Z3 is closed at one point, but with the home relay 71-1 in its ole-energized condition and its front contact 58 open, the auxiliary'stick relay Z8 cannot be picked up. With the control relay Z in its energized condition and home relay 7H d'eenergizedno west bound direction of traffic can be set up in the single track section 0, but if traffic conditions in advance of the signal 8 are favorable, this signal 8will clear andipermit east bound traffic to move. It

is thus noted that if the lever L and L are moved in the sequence L L the auxiliary stick relay ZS will be energized While the auxiliary stick relay ZS will remain dc-energized.

Should now workmen along the track short circuit the track rails, as by getting a crowbar across the rails, the condition of the stick relay ZS could not be disturbed, and eventually the original direction of tratlic would again be set up. In'other words, in the system shown and described, a particular direction of traflic may be set up by the sequence in which control lovers in the tower are moved, and if a certain direction of traffic has once been established this direction of trafiic sons other-than a train moving in that same direction, the direction oi travel originally establ shed will be re-established soon as such relay is re-energized. On the other hand, if the two levers common to a particular single track section are operated in sequence, but are operated one after another with a very short intervening lapse of time,

trafiic is blocked in both directions, because both of relays ZS and ZS will have assumed their energized condition.

The operator. at the tower would, of course, not be informed oi this fact (traiiic blocked in both directions) by the arrangement shown in Fig. 1, and the movement 01" trains might be seriously delayed. F or this reason, it is proposedin accordance with the present invention as shown in Fig; 2, toprovide the train dispatcher with indicating means effective if traffic has been blocked in both directio'iis'in asingle track section by reason of the energized condition of both relays ZS and Z55 In other words, 2 shows the west end of the single track section 0 of the system shown in Fig. lwith the provision of indicating means for indicating when the stick relays ZS and Z8 are both stuck up, the

condition of energization of the relay Z3 being indicated by the condition of the relays 2H and 25. In thisconnection it should be remembered that the relay 2H is. never do energized if an east bound direction of traflic hasbecn set up in the single track section O,

836% Jtin res onse to a de aartin train between the signals 2 and 6, and when there is Y such. an east bound train moving between the relay 2H is open.

signals 2 anc. l the stick relay 2% will be'up. lherela contacts 66 11 116? when an east-bound train e signal 2 or 2 at clear or caution, and is stu 2S (seel ig. l) is picked up through ck up through contacts/68 and'69 1.

-when th ionic relay 2H drops in response to 1 v.-' I 1 4 e such eparting train. In other WOZ'QS, the lelays Ell and'QS are never both de-energized unless the tun'ible-down I circuit controlling V stickrelay Z5 is also in its energized condition,

is clearevidence that both directions of trafii'c are bl cked tor the single track section 9. to, the dispatcher in the tower. DO When the relays 2H and 23 are de-energized and the relay-Z3 is energized.

ltlshould be noted-that the front contac s SOol -relayQH front contact 61 of relay 2S, and the back contacts 52 of the relay Z8 are all connected in multiple with the back contact 63 of the relay OEh-so that if relay '7 is energized rela T 2H is de ener ized and 're layQS is left normal (dc-energized) the contact 63 of the relay OS is unshu'nted and thetrack repeater relay TB which relay repeatsthe detector track relay DT 1 It is believedexpedient to firstbrietly consider how occupancy of the'detector track cir' cuit conta ning track relay isirdicated, ithisleature already "having been described generally in my prior application", see. Nd-

22l,087, filed Sept. 21, 1927, and also disclosed 'in the application otDodgsongSer. its.

, 1-87 ,508, filed April 29,1924; .ln'the towergDO is'located an indicatinglamp 1L, which 13 nreferabl associated witlratrack la out as 1 described in my prior application so as to inform the operator wh ch detector track cir-v suit or the various track circuits under his jurisdiction is occupied. This indicating I lamp IL is controlled in accordance with the position of the lever B and the condition of energization or" theindicating relay IR.

' Let us assume that the operator has moved the leverL (see Fig. 2) to the right hand p0 sition and has thereby caused the relay Z to assume its right hand energized position through closure or he following circuit :'be-

ginning at the battery l(),wire 41', lever L Wire 43, indicating relay IR, wire 45 front contact 43 or the relay ire 43, wit-"idling oi the control relay Z wires' and RC hack to the battery 40. With the lever L on its right hand position the circuit for the indicating lamp IL is completed at the contact D, but the-indicating lamp IE is not illuminated because its circuit is broken at the back contact .64 oftheindicating relay IR. The energization ofthe control relay Z presumably clears either the signal 1 or the signal 2, de pending upon the direction of trafiic'that has been set up in the single track section 0. In

For this reason if the re laysQll and 28. are both de-energlzed and the V lnother words, it is desirable to indicate 7 erefore' effective to control'the circuit for 1.

any event, let us assume that a West bound" train enters upon the detector track, circuit containing the track relay DT 111 response 7 to clearing of the signal 1, and that such treading of the train on this detector-track circuit de-energizesfthe track relay "DT P- With the detector track relay DT de-energized the energizing circuit for therepeater;

track relay TR is broken at'the front-contact 65 of track relayDT Dropping of the repeater track relay TR opens'its con.-

73, neutral contact 4E of-this control relay Z wire 75, back contactt3 of the relay OS, wire 43 winding of the control rel.ay-Z ,Wi;r-es l4:

and 7 6, back to battery 70. The'control relay Z thus remains in the same energized condition. Drop-pingof the'conta'ctil of the re "lay OS however d e-energizesfthe indicating wrelay 1E, and such de-energizatio'n of relay 1R causes the indicating lamp ILito be illuminated through completion of the following c1rcu1t :'-start1ng with the'termina'l B, wire 77, back contact 64 of the-1nd1acting'relayIR,

wire 8, contact Lfiwires 79 and 80, indicating lamp IL, to common return Wire C connected v to the; other sideoi' thevsou rce of energy 7 taining terminal B Clhe train idlSPZlllCllQI/IS thus informed ofithe occupancy of the; detector track circuit inquestion. 7 T

llet ie-now assume that the leverlfighas been returned to the neutral position and that the lever L (see Fig, 1) is :alscin its neutral,

gized condition, this ontheassumption that there'are no trainsfin theisingle track section'Os Let us now assume. tliatthe operator,contrary Ito instructions, he having been. instructed to allow a certain tinieto elapse be tween movement of adjacen levers','inoves the leversL andL yery quickly in succession.

and that both 'o ftherelays Z13 v and ZS (see F ig. .1) will be picked up, because the auxilary relays 5. 155 and ZS both assume:their energized position before the homerelays 7H 7 11 '11 1' 1151 f t -x Chi n (.Lifl i W1 nave -ac sunciein tune uo assome their 'de-energizedposition. This :rapid sequence sof -lever movementwi'll thus cause the auxiliary stick relays E55 and Z55 tobe both stuck up,.thereby causi thehoine relay 7 H and QI-Iboth to beheld de-energized and thereby blocking trafic in both directions. l itli the relays 2H and 'Zllheld desenergized in this way theassociated stick-relays 2S and will of course 78 (of which 73 is not shown) remain Clo-energized. Referring nowto'lTiQ:

a 2 or the draw ngs, and bearing. in mind that position Under-this conditionthehoine relay 2H (see F igs. f1 and-2) assume itsenei relay Z S 'is' energized, it'is noted, that the energizing circuit for the repeater track relay T Ris broken. This causes the relay OS to assume, its de energized condition, thereby causing illumination ottheindicating lamp IL for reasons heretofore given. This illuminationflot the indicat i lamp Il however, is only momentary, be ause de-energization of the relay OS completes an'anxiliary circuit for the repeater track relay TR which circuit maybe traced follows :beginning at theterminal B of a suitable'source ofcurrent, wire 81, back contact 63,01? the relay OS, wires 82 and 83, winding of the repeater track relay/IR, wire-84, front contact of the detector track relay DT wire-85 to theterininal C connected to'the other side of said source.- VVith this circuit completed the repeater track relay is energized thereby re-energizingthe relay OS and again completing the original energizing circuit for the relays Z and'IIl,

and thereby again extinguishing the indicating lampIL. Obviously, this momentary illumination and extinguishing of the indicating lamp IL is repeated in see-saw fashion, and this indicating lamp is caused to flash or blink thus giving an indication to the dispatcher, distinctive from the indication of detector track circuit occupancy, and intorming him that he has operated his levers 7m succession too quickly, and has caused tratfic to be blocked foriboth directions of ,movement in the'single track section 0.

Although the invention hasbeen shown applied to a'system wherein 'detector'track circuit occupancy is indicated by specific means and circuits, it is desired to be understood that any suitable means may he used for indicating track circuit occupancy or that no track circuit occupancy'need be indicated if desired,

tor inst ance, if desired the contactttih in the control circuit for the relay TR may be omitted. In the same way certain other contacts and devices may be omitted so long as the underlying principles of theinvention are carried out. o

Applicant has thus disclosed, not only a system in Which the direction of trafiic set up by sequence of lever movement cannot be accidentally reversethbut has also disclosed I means tordistinctively indicating to the dispatcher over the same line circuit used for controlling the directioi'r of traffic in the single track sectiomthat he has operated his levers too quickly in succession and that he has blocked trafiie in both directions thus informing him that he must return his levers 1 tothe neutral position and must again operate them in sequence allowingsuficienttiine for settingup the direction of tram travel desired. In thisconnection itisto be understood that if the levers for a particular single track section have been operated too quickly in se- 'quence, the indicating lamps'asso'ciated with the two detector track circuits at opposite ends of this single track section are both flashed.

Having thus shown and described one complete embodiment of the invention and having shown rather specific circuit arrangements for accomplishing the results desired, it is desired to be understood that the particular embodiment of the invention illustrated has been selected to disclose the underlying principles thereof, and it is to be understood that various 'said control relays are energized if energized in succession with an intervening period of time, and means for indicating in the dispatchers office when he has moved his levers in succession too quickly. I

2. In a train dispatching system, the combination with a single track section having starting signals located at opposite ends thereof, a dispatchers ollice containing levers for controlling said starting signals, means for clearing a starting signal at one end of said single track section inaccordanc'e with the sequence in which said levers are operatet if they are not operated too quickly in succession, and means in said dispatchers office for indicating when he has operated his levers one after another in less than a predetermined period of time.

3. In a train dispatching system, the conibination with a single track section having a starting signal at each end thereof, a train d'ispatchers oifice, two levers in said office one for each of said startmg signals, interlocking means for permitting only the starting signal controlled by the first lever operated to clear when said two levers are operated in sequence fic, a control relay at each e'ndof said single track section governing the tumble-down circuit governable -from that end controlled by a dispatcher in a distant dispatchers of fice, means for preventing one control relay from controlling its tumble-down circuit, it

'auxiliary.sticlrrelay at each end of a single the, other control relay in the. n'ieantime has tie-energized its tiin'ible-down circuit, and

ineans in the dispatchers ofiice foriindicating' to the dispatcher if he has energized the control relaysso quickly in succession thatthe first control relay tobe energized did not yet effect complete de-energization of the tumbledown circuit it controls before the other control'relay was energized.

5. in combination with a single tracl; railsignalling system of the absolute-permissive-bloch type, of train dispatching means superimposed thereon including an track section of said system, means for interlocking said two auxiliary relays through the medium of'the tumble-down circuits of the absolute-permissive-bloclr system of-said single track section, and means for indicating in a chstant dispatchers oliice when both of these auxil ary stick relays have been energized in response to substantially simultaneous de-energlzatlon of said two tumble down circuits. g

6. In combination with a single track rail;-

way system of the absolute-permissive-block end of said single track section being de-energizedby the control relay at the other end of said single track section if thehome relay at the other end is in its de-energized condition, and an auxiliary relay at each end of saidsingle track section each of which may be energized only if the control relayat that end is energized and the home relay at that end is energized. u 7; In combination with a single track rallrway system of the absolutepermissive-block type including the usual tumble-downcircuits and home relays, a control relay at each end of a single track section for controlling thehome relay at the other end of thesingle track section through a tumbledown circuit, means for preventing the home relay at one end of said single track section being de-energized by the control relay at 1 the other end, of said single track section if gized.

the home relay at the other endis in its deenergized condition, an auxiliary relay at each end of said single track section which may be energized only if the control relay at that end is energized and the home relay at that end is energized, and indicating means for indicating at a distant dispatchers ofl'ice when both ofsaidi auxiliary' relays are ener- 8. In combination witha single track railway system of the absolute-permissive-block type including the usual tumble-down cir-' cuits and home relays, a control relay at each control relay at the otherend of said" single track section if the home relay at the other end is in its de-energized condition, an auxiliary relay at each end of said single track section which may be energized only if the control relay'at that end is energized and the home relay at that end is energized, and indi- V eating means forindicating at a distant dis patchers ofiice when both'of said auxiliary relays are energized, said indicating means informing the dispatcherthat he has operated his levers too quickly in succession I 9; In a'single track-railway signalling system of the absolute-permissive block type in which each of the home relays for each direction of trafiic of a single track section is normally energized by a circuit includingafront contact of the next home'relayahead gov-v ernmg the same directlon of traliic, means at one end of a single track'section for'de-ener glzing the home relays governing traffic in said single track section moving toward that end, and means for manifesting whether the travel were "deenergized when'the home relays in question were being dc-energized.

10. In a single track railway signaling system of theabsolute-permissive-block typeinr cluding tumble-down" circuits in which each of the home relays for each direction of traflic of a single track section are normally energized by a circuit including a front contact of the next home relay ahead governing the samedirection oftrafiic, means at one end of a single track section for de-energizing the tumble-down circuit governing trafic insaid single track section moving toward that end, and'means for manifesting'whether thetumble-down circuit for the opposite direction of traffic was de-energized when the tumblegized.

11. In a single track railway signaling system of the absolute-permissiVe-block type including tumble-down circuits in which each down circuit in question was being de-enerof the home relays for each direction of trafiic of a single track' section is normally energized by a circuit including a front contact of the next home relay ahead governing the same direction of traflic, means at one end of a single track section for de-energizing the tumble-down circuit governing traflic in said single track section moving toward that end, means for manifesting whether the tumbledown circuit for the opposite direction of traffic was de-energized when the tumble- "down circuit in question was being de-energized, and means for indicating when bothof home relays for the opposite direction of' C ix the tumble-down circuits are de-energized substantially simultaneously.

12. In combination with a single track railway signalling system of the absolute-permissive-block type, of train dispatching means superimposed thereon including an auxiliary stick relay at each end of a single track section of said: system means for lnterlocking said two auxiliary relays through the medium of the tumble-down circuits of the absolute-permissive-block system of said single track section, and means for indicating in a distant dispatchers oflice when both of these auxiliary stick relays havebeen energized in response to simultaneous initiation of deenergization of said two tumble-down circuitsin overlapped relation.

13. In combination, a dispatchers office,

two control relays located distant to the disatchers oflice two levers in said ofiice for controlling the energization of said control relays, means responsive to the sequence in which said control relays are energized if energized in succession with at least a predetermined intervening'period of time, and

' means for indicating in the dispatchers oflice when he has moved hls levers 1n succession with a less intervening period of time than said predetermined perlod.

In testnnony whereofI affix my signature.

SEDGWICK N. WIGHT. 

